Removed enforce_pat_expiration feature flag

Administrators can now use the pat expiration setting
to toggle pat expiration.
The setting is defaulted to enabled (existing behavior)
This MR removes the feature flag for this feature.

doc/user/admin_area/settings/account_and_limit_settings.md

@@ -194,10 +194,7 @@ To do this:
 ## Optional enforcement of Personal Access Token expiry **(ULTIMATE SELF)**
 
 > - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/214723) in GitLab Ultimate 13.1.
-> - It is deployed behind a feature flag, disabled by default.
-> - It is disabled on GitLab.com.
-> - It is not recommended for production use.
-> - To use it in GitLab self-managed instances, ask a GitLab administrator to [enable it](#enable-or-disable-optional-enforcement-of-personal-access-token-expiry-feature). **(FREE SELF)**
+> - [Feature flag removed](https://gitlab.com/gitlab-org/gitlab/-/issues/296881) in GitLab 13.9.
 
 GitLab administrators can choose to prevent personal access tokens from expiring
 automatically. The tokens are usable after the expiry date, unless they are revoked explicitly.
@@ -208,23 +205,6 @@ To do this:
 1. Expand the **Account and limit** section.
 1. Uncheck the **Enforce personal access token expiration** checkbox.
 
-### Enable or disable optional enforcement of Personal Access Token expiry Feature **(FREE SELF)**
-
-Optional Enforcement of Personal Access Token Expiry is deployed behind a feature flag and is **disabled by default**.
-[GitLab administrators with access to the GitLab Rails console](../../../administration/feature_flags.md) can enable it for your instance from the [rails console](../../../administration/feature_flags.md#start-the-gitlab-rails-console).
-
-To enable it:
-
-```ruby
-Feature.enable(:enforce_pat_expiration)
-```
-
-To disable it:
-
-```ruby
-Feature.disable(:enforce_pat_expiration)
-```
-
 ## Disabling user profile name changes **(PREMIUM SELF)**
 
 > [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/24605) in GitLab 12.7.

ee/app/models/ee/personal_access_token.rb

@@ -47,8 +47,7 @@ module EE
       end
 
       def enforce_pat_expiration_feature_available?
-        License.feature_available?(:enforce_pat_expiration) &&
-          ::Feature.enabled?(:enforce_pat_expiration, type: :licensed, default_enabled: false)
+        License.feature_available?(:enforce_pat_expiration)
       end
     end
 

ee/changelogs/unreleased/remove-enforce_pat_expiration-ff.yml

+---
+title: Optional enforcement of PAT expiration
+merge_request: 53660
+author:
+type: added

ee/spec/models/ee/personal_access_token_spec.rb

@@ -247,16 +247,13 @@ RSpec.describe PersonalAccessToken do
 
     subject { described_class.enforce_pat_expiration_feature_available? }
 
-    where(:feature_flag, :licensed, :result) do
-      true  | true   | true
-      true  | false  | false
-      false | true   | false
-      false | false  | false
+    where(:licensed, :result) do
+      true   | true
+      false  | false
     end
 
     with_them do
       before do
-        stub_feature_flags(enforce_pat_expiration: feature_flag)
         stub_licensed_features(enforce_pat_expiration: licensed)
       end